The present invention relates to power tools and, more particularly, to a leveling device that indicates when the power tool is in a level position.
In various types of power tools, especially drilling tools, it is desirable to know when the tool is in a horizontal or vertical plane. This is particularly useful when drilling holes for hanging doors or the like when it is desirable to have holes which are in plane with horizontal.
Bubble types of levels have been utilized in power tools. However, these types of leveling devices have various shortcomings. While the bubble level works satisfactorily for horizontal applications, it is still burdensome on the user to view the bubble in between the lines. Ordinarily, these bubble types of levels are not conducive for vertical drilling. Also, due to the vibration of the tool, frothing occurs inside the level, rendering the bubble level useless in many applications.
Another type of measuring device utilizes a simple pendulum with a rigid straight bar connecting the pivot point with a hanging weight together with a cross bar mounted at ninety (90xc2x0) degrees to a vertical bar. The cross bar can be disposed on either side of the pivot point when the pivot level is hung and the weight achieves equilibrium, the cross bar will be positioned in a horizontal plane. Accordingly, the ends may be aligned with two notches on a carrier board to align the board to the horizontal and thus measure the horizontal plane.
Both of these devices require the user to have an accurate view of the level during drilling to maintain the plane of the power tool. Also, while these types of devices may be satisfactory in horizontal drilling planes, they are not particularly useful when used in a vertical drilling arrangement.
Accordingly, it is an object of the present invention to provide a user with an easy to use leveling device. The device indicates to the user, usually by an illuminated light, that horizontal or vertical planes have been achieved. The present invention enables the user to readily establish visual contact to indicate that a desired level position has been achieved.
In accordance with a first embodiment of the present invention, a power tool leveling device comprises a housing with a cavity in the housing. A rotating member is positioned in the housing. The rotating member moves in the cavity such that the rotating member seeks an equilibrium position. The equilibrium position corresponds to a level position. At least one member is associated with the rotating member to enable passage of light through the rotating member. An electrical circuit is associated with the rotating member. The electrical circuit includes an emitting device, a receiving device, and an indicator device. These devices are electrically coupled such that upon activation, the emitting device emits a beam which passes through the at least one member. The beam is received by the receiving device which, in turn, activates the indicator device. The indicator device informs a user that the leveling device is in an equilibrium position. Also, a power source is coupled with the electrical circuit to energize the electrical circuit. The electrical circuit further includes a device for varying current to the indicator device such that as the beam intensity at the receiver device increases, the indicator device increases in intensity. This corresponds to leveling; e.g., as the tool becomes more level, the intensity increases. The device for varying the current is a PNP transistor. The indicator device is a light emitting device. The light emitting device has a variable intensity from off to full on. In the full on position the leveling device is in its level position. The at least one member in the rotating member is an aperture. In an alternate embodiment, the aperture includes a lens for refracting the beam. In a second alternate embodiment, a lens is positioned between the rotating member and the receiving device to refract the beam. Also, the at least one aperture may be an elongated slot. Further, the at least one member may be an optic fiber to transmit the beam. Also, a switch is coupled with the leveling device for activating and deactivating the electrical circuit.
In accordance with a second aspect of the invention, a power tool comprises a housing with a motor in the housing. An output is coupled with the motor. An activation member to energize the motor for rotating the output is coupled with the motor. A power source is electrically coupled with the motor and activation member. A leveling device is present in the housing. The leveling device comprises a housing with a cavity in the housing. A rotating member is positioned in the housing. The rotating member moves in the cavity such that the rotating member seeks an equilibrium position. The equilibrium position corresponds to a level position. At least one member is associated with the rotating member to enable passage of light through the rotating member. An electrical circuit is associated with the rotating member. The electrical circuit includes an emitting device, a receiving device, and an indicator device. These devices are electrically coupled such that upon activation, the emitting device emits a beam which passes through the at least one member. The beam is received by the receiving device which, in turn, activates the indicator device. The indicator device informs a user that the leveling device is in an equilibrium position. Also, a power source is coupled with the electrical circuit to energize the electrical circuit. The electrical circuit further includes a device for varying current to the indicator device such that as the beam intensity at the receiver device increases, the indicator device increases in intensity. This corresponds to leveling; e.g., as the tool becomes more level, the intensity increases. The device for varying the current is a PNP transistor. The indicator device is a light emitting device. The light emitting device has a variable intensity from off to full on. In the full on position the leveling device is in its level position. The at least one member in the rotating member is an aperture. In an alternate embodiment, the aperture includes a lens for refracting the beam. In a second alternate embodiment, a lens is positioned between the rotating member and the receiving device to refract the beam. Also, the at least one aperture may be an elongated slot. Further, the at least one member may be an optic fiber to transmit the beam. Also, a switch is coupled with the leveling device for activating and deactivating the electrical circuit.
In accordance with a third aspect of the invention, a power tool comprises a housing with a motor within the housing. An output is coupled with the motor. An activation member energizes the motor to rotate the output which is coupled with an output source and the motor. A leveling device is coupled with the power tool. The leveling device includes an indicator such that upon activation of the leveling device the indicator indicates to a user that the leveling device is in an equilibrium position. The leveling device is also coupled with the power source. The indicator is positioned on the housing such that a user may view the indicator from all sides of the housing when the power tool is in use. The indicator varies in intensity as the leveling position is reached. The indicator is ordinarily a light emitting device. Accordingly, the light emitting device varies in brightness, being brightest when the power tool is in the level position. Also, a switch is coupled with the activation member for activating the leveling device prior to activating the motor.
From the following detailed description, taken in conjunction with the drawings and subjoined claims, other objects and advantages of the present invention will become apparent to those skilled in the art.